57 research outputs found
Misclassification Risk and Uncertainty Quantification in Deep Classifiers
In this paper, we propose risk-calibrated evidential deep classifiers to reduce the costs associated with classification errors. We use two main approaches. The first is to develop methods to quantify the uncertainty of a classifier’s predictions and reduce the likelihood of acting on erroneous predictions. The second is a novel way to train the classifier such that erroneous classifications are biased towards less risky categories. We combine these two approaches in a principled way. While doing this, we extend evidential deep learning with pignistic probabilities, which are used to quantify uncertainty of classification predictions and model rational decision making under uncertainty.We evaluate the performance of our approach on several image classification tasks. We demonstrate that our approach allows to (i) incorporate misclassification cost while training deep classifiers, (ii) accurately quantify the uncertainty of classification predictions, and (iii) simultaneously learn how to make classification decisions to minimize expected cost of classification errors
What drives Malaysian consumers’ organic food purchase intention? The role of moral norm, self-identity, environmental concern and price consciousness
Purpose
The purpose of this paper is to examine the factors that may affect consumer intention and behaviour to purchase organic food in a non-western context.
Design/methodology/approach
Responses were obtained from 246 organic food consumers using judgemental sampling. Data were analysed using partial least squares–structural equation modelling to examine the strength of the relationships among the constructs.
Findings
The findings reveal that attitude, subjective norm (SN), perceived behavioural control, moral norm (MN), self-identity (SI) and environmental concern (EC) exert significant positive effect on purchase intention (PI). Furthermore, PI is found to mediate the relationship among attitude, SN, perceived behavioural control, MN, SI and EC with purchase behaviour (PB). Moreover, the findings indicate that price consciousness moderates the relationship between PI and PB.
Research limitations/implications
The results of this study emphasised that marketers need to implement various marketing strategies including discount, advertisements and new product development to bring positive change in consumers’ intention and to attract them towards purchasing organic food. Moreover, marketers may take some initiatives to reduce the price of organic food through various strategies which eventually can reduce the cost of organic foods for local consumers.
Originality/value
This study extends the theory of planned behaviour (TBP) by incorporating MN, SI and EC. The expanded theoretical framework improved the predictive ability of the TBP.Scopu
Regulation of the epithelial Na+ channel by Nedd4 and ubiquitination.
The epithelial Na+ channel (ENaC) is comprised of three subunits, alpha, beta and gamma, and plays an essential role in Na+ and fluid absorption in the kidney, colon and lung. We had identified proline-rich sequences at the C termini of alpha beta gamma ENaC, which include the sequence PPxY, the PY motif. This sequence in beta or gamma ENaC is deleted or mutated in Liddle's syndrome, a hereditary form of arterial hypertension. Our previous work demonstrated that these PY motifs bind to the WW domains of Nedd4, a ubiquitin protein ligase containing a C2 domain, three or four WW domains and a ubiquitin protein ligase Hect domain. Accordingly, we have recently demonstrated that Nedd4 regulates ENaC function by controlling the number of channels at the cell surface, that this regulation is impaired in ENaC bearing Liddle's syndrome mutations, and that ENaC stability and function are regulated by ubiquitination. The C2 domain is responsible for localizing Nedd4 to the plasma membrane in a Ca(2+)-dependent manner, and in polarized epithelial MDCK cells this localization is primarily apical. In accordance, electrophysiological characterization of ENaC expressed in MDCK cells revealed inhibition of channel activity by elevated intracellular Ca2+ levels. Thus, in response to Ca2+, Nedd4 may be mobilized to the apical membrane via its C2 domain, where it binds ENaC via Nedd4-WW:ENaC-PY motifs' interactions, leading to ubiquitination of the channel by the Nedd4-Hect domain and subsequent channel endocytosis and lysosomal degradation. This process may be at least partially impaired in Liddle's syndrome due to reduced Nedd4 binding, leading to increased retention of ENaC at the cell surface
Resveratrol augments doxorubicin and cisplatin chemotherapy: a novel therapeutic strategy
Background: The treatment of cancer is a current challenge for public health, causing high rates of morbidity and mortality worldwide. Doxorubicin (DOX) and cisplatin (CP) are two well-known chemotherapeutic agents approved by the Food and Drug Administration to treat cancer patients. However, there are two problems associated with DOX and CP: drug resistance and adverse impact. Resveratrol (Res) belongs to the stilbene class and possesses various health-promoting ef-fects, such as antioxidant, anti-inflammatory, anticancer, hepatoprotective, and neuroprotective effects. Objective: The present review aims to give special attention to the therapeutic impacts of Res in potentiating DOX and CP’s antitumor activities and reducing their side effects. Methods: PubMed, Science Direct, and Google Scholar were used to search articles for the current manuscripts. Results: Co-administration of Res can prevent chemoresistance and potentiate the induction of apop-tosis and cell cycle arrest in cancer cells. Res can enhance the sensitivity of cancer cells to DOX and CP chemotherapy by inhibiting the migration and metastasis of cancer cells. Simultaneously, Res, due to its therapeutic actions ameliorates the adverse impacts of DOX and CP on normal cells and organs, including the liver, kidney, brain, and testes. As Res suffers from poor bioavailability, nanoformulations have been developed with promising results to improve its antitumor activity and protective effects. Conclusion: Based on preclinical studies, it is obvious that Res is a promising adjsuvant for CP and DOX chemotherapy, and its benefits can be utilized in the clinical course
Studies of the Crystallization of Amorphous Trehalose Using Simultaneous Gravimetric Vapor Sorption/Near IR (GVS/NIR) and “Modulated” GVS/NIR
The purpose of this research was to investigate the influence of changes in the amorphous state on the crystallization of trehalose. Amorphous trehalose is known to stabilize biomaterials; hence, an understanding of crystallization is vital. Amorphous trehalose, prepared by spray-drying, was exposed to either a single step (0–75%) in relative humidity (RH) or to modulated 0–75–0% RH to cause crystallization. For the single-step experiment, two samples crystallized in a predictable manner to form the dihydrate. One sample, while notionally identical, did not crystallize in the same way and showed a mass loss throughout the time at 75% RH, with a final mass less than that expected for the dihydrate. The idiosyncratic sample was seen to have a starting near infrared (NIR) spectra similar to that exhibited by anhydrous crystalline trehalose, implying that short-range order in the amorphous material (or a small amount of crystalline seed, not detectable using powder X-ray diffraction) caused the sample to fail to form the dihydrate fully when exposed to high RH. The modulated RH study showed that the amorphous material interacted strongly with water; the intensity of the NIR traces was not proportional to mass of water but rather the extent of hydrogen bonding. Subsequent crystallization of this sample clearly was a partial formation of the dihydrate, but with the bulk of the sample then shielded such that it was unable to show significant sorption when exposed to elevated RH. It has been shown that the nature of the amorphous form will alter the way in which samples crystallize. With oscillation in RH, it was possible to further understand the interactions between water and amorphous trehalose
Biomedical application of chitosan-based nanoscale delivery systems: potential usefulness in siRNA delivery for cancer therapy
Gene therapy is an emerging and promising strategy in cancer therapy where small interfering RNA (siRNA) system has been deployed for down-regulation of targeted gene and subsequent inhibition in cancer progression; some issues with siRNA, however, linger namely, its off-targeting property and degradation by enzymes. Nanoparticles can be applied for the encapsulation of siRNA thus enhancing its efficacy in gene silencing where chitosan (CS), a linear alkaline polysaccharide derived from chitin, with superb properties such as biodegradability, biocompatibility, stability and solubility, can play a vital role. Herein, the potential of CS nanoparticles has been discussed for the delivery of siRNA in cancer therapy; proliferation, metastasis and chemoresistance are suppressed by siRNA-loaded CS nanoparticles, especially the usage of pH-sensitive CS nanoparticles. CS nanoparticles can provide a platform for the co-delivery of siRNA and anti-tumor agents with their enhanced stability via chemical modifications. As pre-clinical experiments are in agreement with potential of CS-based nanoparticles for siRNA delivery, and these carriers possess biocompatibiliy and are safe, further studies can focus on evaluating their utilization in cancer patients
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